You not understanding how insurance actually works doesn’t mean I was talking in circles. We pay for the services that we get through our collective insurance premiums. When things like birth control are added the premiums just go up to compensate. We keep adding things in which is part of why the premiums continue to skyrocket.
I won’t bother getting into how it changes the incentives of consumers. How you are now more likely to choose options that are much more expensive because the relative cost to you is the same at the time of purchase. That is how health providers can sell products that cost 4x as much for the marginal benefit of taking one pill a day versus twice a day for instance. If you doubt this then please find one advertisement for a healthcare related item that mentions the price.